I received a treat and wrote in a 5-minute fandom last year and really enjoyed myself. I liked that there wasn't a lot of canon (or fanon) to deal with, and that what I wrote ended up being totally different than the fic I received.
I feel like I used to see the advice "add a 5-minute to your requests to give your author another option if they sour on the fandom you were matched on" a lot more than I have recently and I'm glad because it's really stupid advice. Like everything else, only request it if you really do want to see fic for it. I feel like some people stick those kinds of fandoms into their requests, but then don't have any prompts so I'm wary of offering a lot of 5-min fandoms.
Re: 5-Minute Fandoms
I feel like I used to see the advice "add a 5-minute to your requests to give your author another option if they sour on the fandom you were matched on" a lot more than I have recently and I'm glad because it's really stupid advice. Like everything else, only request it if you really do want to see fic for it. I feel like some people stick those kinds of fandoms into their requests, but then don't have any prompts so I'm wary of offering a lot of 5-min fandoms.